/**********************************************************\
|                                                          |
| xxtea.js                                                 |
|                                                          |
| XXTEA encryption algorithm library for JavaScript.       |
|                                                          |
| Encryption Algorithm Authors:                            |
|      David J. Wheeler                                    |
|      Roger M. Needham                                    |
|                                                          |
| Code Author: Ma Bingyao <mabingyao@gmail.com>            |
| LastModified: Oct 4, 2016                                |
|                                                          |
\**********************************************************/

// (function (global) {
// 'use strict';

if (typeof (global.btoa) == "undefined") {
    global.btoa = function () {
        var base64EncodeChars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/'.split('');
        return function (str) {
            var buf, i, j, len, r, l, c;
            i = j = 0;
            len = str.length;
            r = len % 3;
            len = len - r;
            l = (len / 3) << 2;
            if (r > 0) {
                l += 4;
            }
            buf = new Array(l);

            while (i < len) {
                c = str.charCodeAt(i++) << 16 |
                    str.charCodeAt(i++) << 8 |
                    str.charCodeAt(i++);
                buf[j++] = base64EncodeChars[c >> 18] +
                    base64EncodeChars[c >> 12 & 0x3f] +
                    base64EncodeChars[c >> 6 & 0x3f] +
                    base64EncodeChars[c & 0x3f];
            }
            if (r == 1) {
                c = str.charCodeAt(i++);
                buf[j++] = base64EncodeChars[c >> 2] +
                    base64EncodeChars[(c & 0x03) << 4] +
                    "==";
            } else if (r == 2) {
                c = str.charCodeAt(i++) << 8 |
                    str.charCodeAt(i++);
                buf[j++] = base64EncodeChars[c >> 10] +
                    base64EncodeChars[c >> 4 & 0x3f] +
                    base64EncodeChars[(c & 0x0f) << 2] +
                    "=";
            }
            return buf.join('');
        };
    }();
}

if (typeof (global.atob) == "undefined") {
    global.atob = function () {
        var base64DecodeChars = [-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1, -1, 63,
            52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -1, -1, -1, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
            15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1, -1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
            41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1
        ];
        return function (str) {
            var c1, c2, c3, c4;
            var i, j, len, r, l, out;

            len = str.length;
            if (len % 4 !== 0) {
                return '';
            }
            if (/[^ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789\+\/\=]/.test(str)) {
                return '';
            }
            if (str.charAt(len - 2) == '=') {
                r = 1;
            } else if (str.charAt(len - 1) == '=') {
                r = 2;
            } else {
                r = 0;
            }
            l = len;
            if (r > 0) {
                l -= 4;
            }
            l = (l >> 2) * 3 + r;
            out = new Array(l);

            i = j = 0;
            while (i < len) {
                // c1
                c1 = base64DecodeChars[str.charCodeAt(i++)];
                if (c1 == -1) break;

                // c2
                c2 = base64DecodeChars[str.charCodeAt(i++)];
                if (c2 == -1) break;

                out[j++] = String.fromCharCode((c1 << 2) | ((c2 & 0x30) >> 4));

                // c3
                c3 = base64DecodeChars[str.charCodeAt(i++)];
                if (c3 == -1) break;

                out[j++] = String.fromCharCode(((c2 & 0x0f) << 4) | ((c3 & 0x3c) >> 2));

                // c4
                c4 = base64DecodeChars[str.charCodeAt(i++)];
                if (c4 == -1) break;

                out[j++] = String.fromCharCode(((c3 & 0x03) << 6) | c4);
            }
            return out.join('');
        };
    }();
}

var DELTA = 0x9E3779B9;

function toBinaryString(v, includeLength) {
    var length = v.length;
    var n = length << 2;
    if (includeLength) {
        var m = v[length - 1];
        n -= 4;
        if ((m < n - 3) || (m > n)) {
            return null;
        }
        n = m;
    }
    for (var i = 0; i < length; i++) {
        v[i] = String.fromCharCode(
            v[i] & 0xFF,
            v[i] >>> 8 & 0xFF,
            v[i] >>> 16 & 0xFF,
            v[i] >>> 24 & 0xFF
        );
    }
    var result = v.join('');
    if (includeLength) {
        return result.substring(0, n);
    }
    return result;
}

function toUint32Array(bs, includeLength) {
    var length = bs.length;
    var n = length >> 2;
    if ((length & 3) !== 0) {
        ++n;
    }
    var v;
    if (includeLength) {
        v = new Array(n + 1);
        v[n] = length;
    } else {
        v = new Array(n);
    }
    for (var i = 0; i < length; ++i) {
        v[i >> 2] |= bs.charCodeAt(i) << ((i & 3) << 3);
    }
    return v;
}

function int32(i) {
    return i & 0xFFFFFFFF;
}

function mx(sum, y, z, p, e, k) {
    return ((z >>> 5 ^ y << 2) + (y >>> 3 ^ z << 4)) ^ ((sum ^ y) + (k[p & 3 ^ e] ^ z));
}

function fixk(k) {
    if (k.length < 4) k.length = 4;
    return k;
}

function encryptUint32Array(v, k) {
    var length = v.length;
    var n = length - 1;
    var y, z, sum, e, p, q;
    z = v[n];
    sum = 0;
    for (q = Math.floor(6 + 52 / length) | 0; q > 0; --q) {
        sum = int32(sum + DELTA);
        e = sum >>> 2 & 3;
        for (p = 0; p < n; ++p) {
            y = v[p + 1];
            z = v[p] = int32(v[p] + mx(sum, y, z, p, e, k));
        }
        y = v[0];
        z = v[n] = int32(v[n] + mx(sum, y, z, n, e, k));
    }
    return v;
}

function decryptUint32Array(v, k) {
    var length = v.length;
    var n = length - 1;
    var y, z, sum, e, p, q;
    y = v[0];
    q = Math.floor(6 + 52 / length);
    for (sum = int32(q * DELTA); sum !== 0; sum = int32(sum - DELTA)) {
        e = sum >>> 2 & 3;
        for (p = n; p > 0; --p) {
            z = v[p - 1];
            y = v[p] = int32(v[p] - mx(sum, y, z, p, e, k));
        }
        z = v[n];
        y = v[0] = int32(v[0] - mx(sum, y, z, 0, e, k));
    }
    return v;
}

function utf8Encode(str) {
    if (/^[\x00-\x7f]*$/.test(str)) {
        return str;
    }
    var buf = [];
    var n = str.length;
    for (var i = 0, j = 0; i < n; ++i, ++j) {
        var codeUnit = str.charCodeAt(i);
        if (codeUnit < 0x80) {
            buf[j] = str.charAt(i);
        } else if (codeUnit < 0x800) {
            buf[j] = String.fromCharCode(0xC0 | (codeUnit >> 6),
                0x80 | (codeUnit & 0x3F));
        } else if (codeUnit < 0xD800 || codeUnit > 0xDFFF) {
            buf[j] = String.fromCharCode(0xE0 | (codeUnit >> 12),
                0x80 | ((codeUnit >> 6) & 0x3F),
                0x80 | (codeUnit & 0x3F));
        } else {
            if (i + 1 < n) {
                var nextCodeUnit = str.charCodeAt(i + 1);
                if (codeUnit < 0xDC00 && 0xDC00 <= nextCodeUnit && nextCodeUnit <= 0xDFFF) {
                    var rune = (((codeUnit & 0x03FF) << 10) | (nextCodeUnit & 0x03FF)) + 0x010000;
                    buf[j] = String.fromCharCode(0xF0 | ((rune >> 18) & 0x3F),
                        0x80 | ((rune >> 12) & 0x3F),
                        0x80 | ((rune >> 6) & 0x3F),
                        0x80 | (rune & 0x3F));
                    ++i;
                    continue;
                }
            }
            throw new Error('Malformed string');
        }
    }
    return buf.join('');
}

function utf8DecodeShortString(bs, n) {
    var charCodes = new Array(n);
    var i = 0,
        off = 0;
    for (var len = bs.length; i < n && off < len; i++) {
        var unit = bs.charCodeAt(off++);
        switch (unit >> 4) {
            case 0:
            case 1:
            case 2:
            case 3:
            case 4:
            case 5:
            case 6:
            case 7:
                charCodes[i] = unit;
                break;
            case 12:
            case 13:
                if (off < len) {
                    charCodes[i] = ((unit & 0x1F) << 6) |
                        (bs.charCodeAt(off++) & 0x3F);
                } else {
                    throw new Error('Unfinished UTF-8 octet sequence');
                }
                break;
            case 14:
                if (off + 1 < len) {
                    charCodes[i] = ((unit & 0x0F) << 12) |
                        ((bs.charCodeAt(off++) & 0x3F) << 6) |
                        (bs.charCodeAt(off++) & 0x3F);
                } else {
                    throw new Error('Unfinished UTF-8 octet sequence');
                }
                break;
            case 15:
                if (off + 2 < len) {
                    var rune = (((unit & 0x07) << 18) |
                        ((bs.charCodeAt(off++) & 0x3F) << 12) |
                        ((bs.charCodeAt(off++) & 0x3F) << 6) |
                        (bs.charCodeAt(off++) & 0x3F)) - 0x10000;
                    if (0 <= rune && rune <= 0xFFFFF) {
                        charCodes[i++] = (((rune >> 10) & 0x03FF) | 0xD800);
                        charCodes[i] = ((rune & 0x03FF) | 0xDC00);
                    } else {
                        throw new Error('Character outside valid Unicode range: 0x' + rune.toString(16));
                    }
                } else {
                    throw new Error('Unfinished UTF-8 octet sequence');
                }
                break;
            default:
                throw new Error('Bad UTF-8 encoding 0x' + unit.toString(16));
        }
    }
    if (i < n) {
        charCodes.length = i;
    }
    return String.fromCharCode.apply(String, charCodes);
}

function utf8DecodeLongString(bs, n) {
    var buf = [];
    var charCodes = new Array(0x8000);
    var i = 0,
        off = 0;
    for (var len = bs.length; i < n && off < len; i++) {
        var unit = bs.charCodeAt(off++);
        switch (unit >> 4) {
            case 0:
            case 1:
            case 2:
            case 3:
            case 4:
            case 5:
            case 6:
            case 7:
                charCodes[i] = unit;
                break;
            case 12:
            case 13:
                if (off < len) {
                    charCodes[i] = ((unit & 0x1F) << 6) |
                        (bs.charCodeAt(off++) & 0x3F);
                } else {
                    throw new Error('Unfinished UTF-8 octet sequence');
                }
                break;
            case 14:
                if (off + 1 < len) {
                    charCodes[i] = ((unit & 0x0F) << 12) |
                        ((bs.charCodeAt(off++) & 0x3F) << 6) |
                        (bs.charCodeAt(off++) & 0x3F);
                } else {
                    throw new Error('Unfinished UTF-8 octet sequence');
                }
                break;
            case 15:
                if (off + 2 < len) {
                    var rune = (((unit & 0x07) << 18) |
                        ((bs.charCodeAt(off++) & 0x3F) << 12) |
                        ((bs.charCodeAt(off++) & 0x3F) << 6) |
                        (bs.charCodeAt(off++) & 0x3F)) - 0x10000;
                    if (0 <= rune && rune <= 0xFFFFF) {
                        charCodes[i++] = (((rune >> 10) & 0x03FF) | 0xD800);
                        charCodes[i] = ((rune & 0x03FF) | 0xDC00);
                    } else {
                        throw new Error('Character outside valid Unicode range: 0x' + rune.toString(16));
                    }
                } else {
                    throw new Error('Unfinished UTF-8 octet sequence');
                }
                break;
            default:
                throw new Error('Bad UTF-8 encoding 0x' + unit.toString(16));
        }
        if (i >= 0x7FFF - 1) {
            var size = i + 1;
            charCodes.length = size;
            buf[buf.length] = String.fromCharCode.apply(String, charCodes);
            n -= size;
            i = -1;
        }
    }
    if (i > 0) {
        charCodes.length = i;
        buf[buf.length] = String.fromCharCode.apply(String, charCodes);
    }
    return buf.join('');
}

// n is UTF16 length
function utf8Decode(bs, n) {
    if (n === undefined || n === null || (n < 0)) n = bs.length;
    if (n === 0) return '';
    if (/^[\x00-\x7f]*$/.test(bs) || !(/^[\x00-\xff]*$/.test(bs))) {
        if (n === bs.length) return bs;
        return bs.substr(0, n);
    }
    return ((n < 0xFFFF) ?
        utf8DecodeShortString(bs, n) :
        utf8DecodeLongString(bs, n));
}

function encrypt(data, key) {
    if (data === undefined || data === null || data.length === 0) {
        return data;
    }
    data = utf8Encode(data);
    key = utf8Encode(key);
    // console.log(toBinaryString(encryptUint32Array(toUint32Array(data, true), fixk(toUint32Array(key, false))), false))
    return toBinaryString(encryptUint32Array(toUint32Array(data, true), fixk(toUint32Array(key, false))), false);
}

function encryptToBase64(data, key) {
    return global.btoa(encrypt(data, key));
}

function decrypt(data, key) {
    if (data === undefined || data === null || data.length === 0) {
        return data;
    }
    key = utf8Encode(key);
    return utf8Decode(toBinaryString(decryptUint32Array(toUint32Array(data, false), fixk(toUint32Array(key, false))), true));
}

function decryptFromBase64(data, key) {
    if (data === undefined || data === null || data.length === 0) {
        return data;
    }
    return decrypt(global.atob(data), key);
}

export default {
    utf8Encode: utf8Encode,
    utf8Decode: utf8Decode,
    encrypt: encrypt,
    encryptToBase64: encryptToBase64,
    decrypt: decrypt,
    decryptFromBase64: decryptFromBase64
};
// })(this || [eval][0]('this'));
